Pirelli’s signature yellow thermoplastic polyurethane (TPU) inner tubes now have an “RS” version to match their top-of-the-line tube-type road bike tires…like the P-Zero Race RS launched in March.
The weight savings and claimed (up to) 12% reduction in rolling resistance come from a new TPU formulation, plus a minimalist Presta valve with non-replaceable, non-repairable glued core. In fact, they don’t want you patching or repairing these either…such is the cost of ultimate performance.
Despite that race day-only vibe, the tube wall is actually 32% thicker than the prior Smartube, offering a bit more puncture protection (and TPU tubes are already more puncture resistant than standard butyl rubber inner tubes). Here’s the comparison:
Note the sizes measured…the RS tube is bigger, designed for 26mm to 35mm wide tires, and it’s still a few grams lighter than the original Smartube for 23-32mm tires.
Weights shown are for tubes with 42mm valve stems, they also offer 60mm (33g) and 80mm (34g) options.
They’re as fast as going Tubeless
And here’s how their performance compares to tubeless, which is surprisingly close. Assuming you’re using Pirelli RS tires, the tube-type tire with Smartube RS is actually lighter than a TLR tire with sealant, and only 0.2W slower.
So, if you’ve been the holdout on going tubeless, now you can brag to your future-forward friends that you were right all along.
Thankfully, the valve stem is black, so they’ll look normal on any bike. They’re rated solely for use with disc brakes, no rim brakes allowed. So, you’ll have to be a little future forward even if you are still (and now justifiably so) running tubes. MSRP $37.50 each.
